Professional athletes caught on a few years ago. Minnesota Vikings linebacker Jasper Brinkley just started using it to help come back from a season-ending hip injury.

“The wear and tear of just working out hard, having a hard workout and once you get out of (Cryo Sauna), you don’t have any pain,” said Brinkley.

Cryo Sauna opened three months ago in the Medical Arts Building in downtown Minneapolis to the public, and it’s the only one of its kind in the Twin Cities.

“The after effects are beautiful,” said Anderson. “My workouts are longer, my stamina, my joints are better, my skin is better, overall healthy. I feel vibrant and energetic when I use it.”

Here’s how it works: Step inside the booth, wearing only your underwear. The padded chamber fills with bursts of sub-zero nitrogen. Grin and bear it for two-and-a-half minutes, and your body does the rest.

“I’m able to affect the mind in a way that says ‘what are my optimum levels?'” said Johnson. “I’ve put you under so much stress, your mind under so much stress it pushes your body to say, ‘ok what works best for me?'”

There’s no apparent risk of frostbite because the air is dry, and you’re not exposed that long. The theory behind the therapy is that your body is so cold, it goes into survival mode. The blood in the body rushes to your core.

“It also begins to pick up those extra enzymes and nutrients your body would normally store and it releases them when you get out,” Johnson said.

When you step out of the machine, blood rushes back to your arms and legs.

“During this process it actually lifts your red blood cell count throughout the body as a defense mechanism,” Johnson said.

Experts say when your body is exposed to these conditions, your body burnscaloriestrying to stay warm. The claim here is that the same day you use Cryo Sauna, you can burn up to 800calories.

However, doctors aren’t yet convinced of all the benefits.

“The jury is still out, it’s too early to know,” said Dr. Gary Collins at Regions Hospital in St. Paul. “We don’t have enough data yet to know if there’s a long lasting benefit, if it would work in everybody, which patient populations it would work best for and then of course the long term side effects.”

Customers swear by the benefits. Anderson, who began using Cryo Sauna to help train for a marathon, freezes about once every three days at $85 a session.

She loves what it does to her skin, saying it’s brighter, tighter and looks younger.

Hamish “The Trainerator” Ganga is a personal trainer. He uses Cryo Sauna to relieve his tendinitis. He said the treatment made the paint go away “just like that.”

“I could not bench press 225 (pounds) in the morning. After (Cryo Sauna), I went back (to the gym) and bench pressed the heaviest I’ve ever done, which was 475 (pounds). And, that’s with no pain,” said Ganga.

If you’re allergic to the cold or have hypertension, you should talk with their doctor before trying cryotherapy. One session costs $85. There are packages available, but don’t expect your insurance to cover the cost of this treatment.